A number of researches are being conducted to provide various types of multimedia services such as a voice service and to support high quality and high speed of data transmission in a wireless communication environment. Technologies associated with a multiple-input multiple-output (MIMO) communication system using multiple channels are in rapid development.
In a MIMO communication system, a base station and terminals may adopt a codebook in order to effectively use channel information and the like. A particular space may be quantized into a plurality of vectors. The plurality of vectors that is generated by quantizing the particular space according to a predetermined standard may be stored in the base station and the terminals as the codebook.
For example, each of the terminals may select any one matrix or vector from matrices or vectors included in the codebook, based on a channel that is formed between the base station and each of the terminals. The base station may also receive the selected matrix or vector to thereby identify the channel information based on the codebook. The selected matrix or vector may be used when the base station generates a transmission signal.
Researches regarding effective codebook design schemes where the transmission signal is single-polarized are being conducted. However, researches associated with determining a type of codebook to improve the throughput of a communication system where the transmission signal is multi-polarized have been insufficient so far. Accordingly, there is a need for an effective codebook design method where a transmission signal is multi-polarized.